With the advent of guns and firearms much effort has been devoted to their perfection in the art of firing projectiles to hit specified targets. An important factor relating to the firing of a gun is the hit probability of the weapon.
A shotgun increases the hit probability by firing multiple projectiles in a random dispersion. An automatic weapon increases the hit probability by firing a random dispersion of projectiles toward a target, thereby covering a broad area around a target and assuring a greater chance of striking the target. Multiple projectiles can be fired simultaneously from a rifle or handgun to increase the hit probability of the weapon.
Much of the prior art for multiple projectile segment cartridges that fire multiple projectiles simultaneously from a single cartridge is from the late 1800's. Nolan (U.S. 221,249 Filed Nov. 4, 1879) uses a multiple projectile segment projectile. Most of the projectile segments that are side by side are held together temporarily after firing by “caps with spurs”, “or soldering” on the forward pointed end, and a “beveled flange” on the aft end. The width of the dispersion is regulated somewhat by the deceleration of the projectile and the resulting force between the forward segments and the aft full caliber projectile segment which separate in flight. “The projectile can be used in either muzzle loading or breech loading arms . . . ”
Rice (U.S. 216,974 Filed Jul. 1, 1879) uses a multiple projectile segment cartridge where pointed projectile segments are side by side. However, Rice apparently uses a smooth bore gun. The cartridge has a “conical or equivalent opening left at the point” and the projectile segments “move in different courses because of their particular shape and because of the action of the air, which spreads them apart as they are shot through it.”
Both of these patents are similar to the applicant's invention, in that multiple projectile segment are fired. However the methods used in these patents, such as “caps with spurs” or “conical or equivalent opening left at the point,” will not fire the projectile segments in accurate repeatable symmetrical patterns compared to the applicant's invention, or be as efficient in hitting the target with projectile segments that retain their velocity, and have a high sectional density because they are spinning around their fore and aft axis, which causes significantly higher terminal effects.
In 1952 a report for the U.S. Army by the Operations Research Office “Operational Requirements for an Infantry Hand Weapon” (3) analyzed firing a salvo of 5 projectiles in a diamond shaped pattern, and found the concept would greatly increase the hit probability of a weapon. With the “pattern-dispersion principle” each projectile had a predetermined hit point in the dispersion, was separated from the other projectiles, and the diamond shaped salvo efficiently maximized the lethal area, and. the hit probability of the dispersion. Graphs of the hit probability of the diamond shaped dispersion at different ranges and aiming errors, along with probability tables that predicted the number of projectiles that would strike the target at a given range were included in the report.
Several multi-barreled weapons that fire projectiles simultaneously to form patterns were tested during Project Salvo (1952-1962). These weapons were discontinued after Project Salvo. These weapons failed to provide a solution to the longfelt need of simultaneously firing a salvo of projectiles in a pattern.
The U.S. Army determined that the “pattern salvo weapon” or “dispersion weapon” would be very effective and recommended that the Ordinance Corp. proceed to develop a pattern salvo weapon for the Infantry. “Operational Requirements” (page 34) “the point of chief concern, however is to strive for the attainment of the pattern dispersion principle so that the greatest possible gains can be derived, and in that striving let the engineering difficulties argue for themselves.” It was assumed that a weapon would be produced, and in “Operational Requirements” (pages 31-32) the “Basis of Issue” for the “dispersion weapon” that was recommended was“ . . . 7 in every 10 infantry hand weapons should have the characteristics desirable for short range use.”
However a practical “dispersion weapon” that fired the 5 shot diamond shaped pattern was never developed.